What happens to blood sugar levels in the postabsorptive state?

In the postabsorptive state, which occurs several hours after eating, the body shifts its energy metabolism from utilizing glucose from recent meals to tapping into stored energy sources. During this state, blood sugar levels are maintained through the action of hormones like glucagon and epinephrine.

Glucagon, released from the alpha cells of the pancreas, plays a key role in increasing blood sugar levels. It promotes gluconeogenesis, the process of producing glucose from non-carbohydrate sources, and glycogenolysis, the breakdown of glycogen stored in the liver into glucose. These processes ensure that blood glucose levels remain adequate to meet the energy demands of the body, especially for the brain and other vital organs that rely heavily on glucose.

This hormonal regulation is crucial because, in the postabsorptive state, the direct source of glucose from food has diminished, and the body must rely on its internal mechanisms to sustain blood glucose levels. Therefore, the correct answer highlights how glucagon increases blood sugar levels through these metabolic pathways during this fasting state.